1. Technical Field
The present invention relates to a fastening assembly and, more particularly, to a fastening assembly co-molded with a foam article.
2. Description of Related Art
The conventional hook-and-loop fastener, or better known by the brand name Velcro, was invented by George de Mestral, a Swiss engineer, under the inspiration of burrs. The hook-and-loop fastener comprises a hook side where tiny hooks are disposed thereon and a loop side covered with even smaller and finer loop-like fastening structures. When the hook side and the loop side are pressed together, the hooks on the hook side engage with the loop-like fastening structures on the loop side so that the two sides are fastened together.
In recent years, the hook-and-loop fastener, which is easily assembled and detached, is often coupled and used with other articles. When a hook-and-loop fastener is applied to a foam article such as a seat cushion, a buffer pad, and so on, the hook-and-loop fastener is bonded to the foam article with the hook side facing outward so as to fasten with another article having a corresponding loop side. Typically, a seat cushion with a hook-and-loop fastener is manufactured by placing the hook-and-loop fastener at a predetermined location in a mold and introducing a foam material into the mold. The foam material is then co-molded with the hook-and-loop fastener and, when completely set, takes on the shape defined by the mold. However, during the foaming process, the foam material tends to cover the hooks of the hook-and-loop fastener so that, after the foam material is set, the hooks of the hook-and-loop fastener cannot fasten with corresponding fastening structures. Thus, a defective product is produced, and the production cost is wasted. To prevent the foam material from damaging the hooks and consequently the hook-and-loop fastener, a traditional approach is to cover the hooks temporarily with an extra protective film, which is removed after the foam material is co-molded with the hook-and-loop fastener.
In addition, while the foam material expands, the expanding foam material produces a pushing force in all directions. If the hook-and-loop fastener is not securely positioned at the predetermined location in the mold, the pushing force generated during the foaming process will push the hook-and-loop fastener away from the predetermined location so that the molded product is defective, with the hook-and-loop fastener displaced.
In order to overcome the aforesaid drawback, it has been proposed, as in U.S. Pat. No. 4,693,921, to place a temporary protective film comprising an iron sheet over the hook-and-loop fastener so as to protect the hooks on a fastening side thereof from being covered by the foam material during the foaming process and allow the hook-and-loop fastener to be attracted and thus secured in position to a magnet on the mold. However, this temporary protective film has to be removed after the molding process by heating or by use of chemicals, which involves a complicated removing procedure and is very inconvenient.